Watson and Crick Metal Base Pair from Model

This is one of four brass templates illustrating the base pairings of adenine and thymine or cytosine and guanine, from Francis Crick's and James Watson's original model of the "double helix" of DNA. Two templates show the correct base pair shapes; two others are earlier, misconceived models. In his book, The Double Helix, Watson recounts the moment he and Crick assembled the first correct model. A key clue for matching the correct forms of adenine and thymine or guanine and cytosine came from American crystallographer Jerry Donohue, who worked in the same laboratory as Watson and Crick. Data from Donohue and other crystallographers, including Rosalind Franklin, was key to Watson and Crick’s success. After the double helix research was published in Nature, generating tremendous worldwide notoriety, Donohue kept the model templates as souvenirs. Later, he returned to the United States, taking a position at the Fox Chase Cancer Center in Philadelphia. Shortly before his death, Donohue gave the templates to his friend and fellow crystallographer, Dr. Helen Berman, who presented them to the Smithsonian in 1988.
Currently not on view
Date made
Crick, Francis
Watson, James
Cavendish Laboratory
Physical Description
brass (overall material)
overall: 2 cm x 24 cm x 8 cm; 13/16 in x 9 7/16 in x 3 1/8 in
ID Number
accession number
catalog number
Credit Line
Helen Berman, Ph.D.
See more items in
Medicine and Science: Medicine
Science & Mathematics
Data Source
National Museum of American History


Where is the original model built by Watson & Crick located? Is it available for public viewing?

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